Americans believe in freedom of information but they also believe in the right to exercise some say over what their children read. That's what creates the drama over the American Library Association's annual most-challenged book list, and this year – in which Stephenie Meyer's fantastically popular "Twilight" teen vampire series landed at spot No. 5 – is no exception.

The list is generated by formal requests to remove books from US public schools and libraries. The top slots on the 2009 list include some familiar titles and some new names. The "Twilight" series, making its first appearance in the top 10, was challenged because they were deemed to be sexually explicit, to include offensive religious views, and to be unsuitable for young-adult readers.

The number of book challenges actually dropped last year. ALA recorded 460 challenges in 2009, a drop from 513 the year before (although the ALA estimates that its list only reflects about 25 percent or less of the challenges actually made). In any given year, however, very few challenges actually result in a book being removed from a school or library.

“Even though not every book will be right for every reader, the ability to read, speak, think and express ourselves freely are core American values,” said Barbara Jones, director of the ALA’s Office for Intellectual Freedom. “Protecting one of our most fundamental rights – the freedom to read – means respecting each other’s differences and the right of all people to choose for themselves what they and their families read.”

The "Twilight" books were not the most challenged books in the country last year. That distinction went to "ttyl," by Lauren Myracle, a book series aimed at young-adult readers and written in the form of instant messages.

Other books in the top 10 included often-challenged classics like "To Kill a Mockingbird" by Harper Lee (objected to by readers who deemed it racist, offensive in its language, and unsuitable for young readers) and "Catcher in the Rye,” by J.D. Salinger (judged to be sexually explicit, offensive in its language, and unsuitable for young readers).